I. Field of the Invention
The present invention generally relates to the field of five bar linkages and, in particular, the present invention is concerned with five bar linkages wherein any one of the bars of the linkage mechanism is intermittently rigidly joined to an adjacent bar.
II. Description of the Prior Art
Four bar linkage mechanisms are known. My U.S. Pat. No. 4,329,867 describes a press for forming complementary parts having a four bar articulating frame. In a first position the upper and lower bolster plates of the press are spaced apart in a parallel, opposed manner. When the frame is articulated from the first position to a second position, the bolster plates are in a non-parallel, nonopposed arrangement which enables the die or workpiece in the upper bolster to be approached for rework or changing from a convenient angle. While this four bar linkage mechanism provides a convenient arrangement of the bolster plates for removing finished parts and reworking or otherwise modifying the dies, the bolsters cannot be moved to a convenient position where they are non-opposed and parallel.